1. Field of the Invention
The present invention relates to a resist pattern-forming method, and a composition for forming a resist underlayer film.
2. Discussion of the Background
In attempts to improve integrity along with miniaturization of semiconductor devices, etc., miniaturization of a processing size by multilayer resist processes using a resist underlayer film has progressed. Among such multilayer resist processes, a multilayer resist process in which a resist underlayer film is a silicon-containing film will be explained below. First, a resist underlayer film is provided on a substrate to be processed using a composition for forming a resist underlayer film containing a polysiloxane, and thereafter a resist film that is an organic film having a different etching selectivity from that of the resist underlayer film is provided using a photoresist composition. Next, the resist film is exposed through a mask pattern and developed by a developer solution such as an aqueous alkali solution to obtain a resist pattern. Subsequently, the resist pattern is transferred to the resist underlayer film by dry-etching. Finally, the pattern is transferred to the substrate to be processed by dry-etching to obtain a substrate provided with a desired pattern (see Japanese Unexamined Patent Application, Publication Nos. 2001-284209, 2010-85912 and 2008-39811).
Today, also in the case in which such a multilayer resist process is used, further miniaturization of a pattern has been demanded. However, when a composition containing a conventional polysiloxane is used as a resist underlayer film, along with miniaturization of a pattern, a pattern collapse of a resist pattern formed on the resist underlayer film becomes likely to occur. Therefore, a composition for forming a resist underlayer film has been demanded to improve a pattern collapse resistance of a resist pattern.
On the other hand, as a developer solution that develops a resist film, a technique in which an organic solvent having a lower polarity than an aqueous alkali solution is used has been known (see Japanese Unexamined Patent Application, Publication No. 2000-199953). In the case in which development is carried out using such an organic solvent, an optical contrast can be improved, and as a result, a finer pattern can be formed. Therefore, a resist pattern-forming method and a composition for forming a resist underlayer film capable of forming a resist pattern excellent in pattern collapse resistance have been demanded not only in the case of a development with an alkali but also particularly, in the case of a development with an organic solvent.